Reversible vane type fluid motor



Sept 16, 1941- lcz. M. KENDRICK 2,255,786

REVERSIBLE VANE TYPE FLUID MOTOR Filed sept. 14, 1940 2 Sheets-Sheet 1y'. 4,2 Y LW' :g: 7////:7//// 626,0 N 70 ZZ T l f L 43 i 3 k WQ' gf/@.2,15'

ffm 5w w f MW ATTORNEYS Sept. 16, 1941.

c. M. KENDRlcK REVERSBLE VANE TYPE FLUID MOTOR Filed Sept. 14, 1940 2Sheets-Sheet 2 INVENToR Cigar/e5 M25/raffin?" Wi/, g M mf y AToRN/zPatented Sept. 16, 1941 REVERSIBLE VANE TYPE FLUID MOTOR Charles M.Kendrick, New York, N. Y., assigner to Manly Corporation, Washington, D.C., a corporation of Delaware Application September 14, 1940, Serial No.356,734

13 Claims.

This invention relates to reversible rotary uid motors and is concernedmore particularly with motors of this sort in which the rotor isprovided with a plurality of vanes arranged to move inwardly andoutwardly thereof, for example, in a substantially radial direction,during the operation of the device. The present application is acontinuation in part of a copending application filed March 28, 1938,Serial No. 198,449.

Fluid motors of this general class nd their widest use at present ashydraulic devices, that is, devices for handling or whose motive uid isa liquid, such, for example, as oil, and the motor of the presentinvention will be described in connection with such use. It willfbeunderstood, however, that the invention is applicable to motorsoperating with elastic uids.

Vane type motors of this character are provided with a vane track whichis adapted to contact the exposed ends of the vanes and to guide andcontrol the inward and outward movement of the vanes. During operationof the device the vane track also cooperates with one or more of thevanes to radially separate the high pressure fluid area, on at least oneof its circumferential ends, from the adjoining low pressure fluid arca.The other end of the high pressure fluid area is also preferably definedby cooperation between another part of the vane track and one or more ofthe vanes, although this separation is sometimes effected by cooperationof a part of the vane track and some other member of the rotaryassembly, such as the rotor. It is essential that this cooperatingcontact between the fluid separating vane or vanes and the vane track bemaintained in order for the motor to function. It is also important andpractically essential to maintain the exposed ends of the vanescontinuously in contact with the vane track in order to obtain smooth,quiet and satisfactory operation of the device.

The principal object of this invention is to provide a reversible rotaryvane type fluid motor capable of starting smoothly and operatingsatisfactorily'at low rotative speeds as well as at higher speeds ineither direction of rotation of its rotor.

Another object is to provide a reversible vane type fluid motor of thischaracter that is simple in structure and inexpensive to manufacture.

A further and more specific Aobject is to provide an improved rotaryvane type fluid motor embodying simple and improved means for urging thevanes outward to maintain the necessary contact between the ends of saidvanes and the vane track at; all speeds of the rotary assembly and inboth directions of rotation.

Other and more specific objects will appear from the description whichfollows.

The invention will be understood from a consideration of theaccompanying drawings which illustrate, by way of example, embodimentsof the invention in a fluid motor in which the vanes move outwardly andinwardly of the rotor in a substantially radial direction.

In the accompanying drawings:

Fig. 1 is a view, partly schematic, showing a side elevation of a fluidmotor and its connections according to the present invention.

Fig. 2 isA an enlarged longitudinal sectional View, taken through thecenter line of the motor shown in Fig. 1.

Figs. 3 to 5 are sectional views transverse the axis of rotation of therotary assembly, partly in section, drawn to the same scale as Fig. 2and in which:

Fig 3 is taken along the line 3 3 of Fig. 2 looking in the direction ofthe arrows, showing the rotor and its vanes and rother partsof the fluidmotor.

Fig. 4 is a view along the line 4-4 of Fig. 2, corresponding to Fig. 3but looking in the opposite direction as indicated by the arrows andshowing the rotor side of the cover end plate.

Fig. 5 is a view taken along the line 5--5 of Fig. 2, showing the fluidchannels and their connections.

Fig. 6 is a view, partly schematic, corresponding generally to Fig. lbut showing a modification.

Referring first to the embodiment illustrated in Figs. 1 to 5 the fluidcircuit includes a uid supply pipe 38 through which working pressure uidfor operation of the vane type fluid motor is supplied by any suitablesource of pressure fluid, not shown. The fluid supply pipe 38 connectswith the inlet port of a conventional reversing valve having the exhaustport thereof connected with pipe 92 leading to the reservoir, not shown.The reversing valve 90 is also provided with two ports which areconnected with fluid conduits 42 and 43 leading to the fluid channels 40and 4| respectively of the vane type fluid motor, to be hereinafter morefully described. The arrange.- ment'is such that with the rotatable body9| of the reversing valve 90 in the position shown in Fig. 1, theworking pressure fluid from the supply pipe 38 will pass into theconduit 42 and fluid discharged by the vane type motor will pass outfrom said motor through the conduit 43 and into the exhaust pipe 92.Rotation of the rotatable body 9| through-90 in a clockwise directionreverses these fluid connections and the flow of the fluid to and fromthe vane type motor, so that working pressure iiuid then passes into theconduit 43 and fluid exhausted by the motor passes out through theconduit 42 and into the exhaust pipe 92.

As shown in Fig. 2 the motor includes a casing I and cover |I whichcooperate to form a cavity for the 'usual rotor I5 and associated parts.The rotor I is formed with a pair of hubs I6 by'which it is rotatablysupported in a pair of bushings I1 carried by the casing I0 and coverrespectively. 'Ihe rotor also has a plurality of vanes I9 which aremovable ina substantially radial direction inward and outward in thevane slots |8.

The motor shaft 22 is revolubly supported upon a pair of bearing members23' carried by the casing I0 and cover I| respectively and passesthrough the central bore of the rotor I5, vwith which it has a slidablesplined connection as at 2| (Fig. 3). One end of the shaft 22, shown asbroken oi in Fig. 2, projects outward beyond the casing I0 forconnection to the apparatus to be operated by the motor.

A vane track ring (Figs. 2 and 3) surrounds the rotor and vane assemblyand its inner circumferential surface 26 forms a track a-dapted tocontact the outer ends of the vanes I9; for convenience this surface 26will be termed the vane track. The vane track 26 is of variable diameterbut its curvature is preferably symmetrical on either side of a linepassing through the center ofthe rotor |5.

. The motor here illustrated is of the hydraulically balanced doubleacting type of hydraulic device in which each vane is reciprocated twicefor each revolution of the rotor. As shown in 3 the space intermediatethe periphery of the rotor I5 and the vane track 2'6 is accordinglydivided into two uid sections by means oi two sealing chambers formed bycooperation of the rotor I5 and the ends of the vanes I9 with the vanetrack 26 at the region of the vane tracks least diameter, which in thisinstance is adjacent the horizontal center line. The vane track 26 ispreferably provided at each of these points of division or sealingchambers with an. arc 21 (termed the sealing arc) substantiallyconcentric with the rotor I5 and extending in a circumferentialdirection for a distance equal at least to the angular distance betweena pair of adjacent vanes I9, in order that there shall be substantiallyno radial movement of the vanes I9 while passing thereacross. f

Each fluid section includes a working space or chamber 3| (Fig. 3)flanked by a uid area 29 and a fluid area 30, one of which will be theinlet area for that uid section and the other of which will be theoutlet area for that fluid section depending upon the direction of ow ofthe uid in the conduits 42 and 43 and hence upon the direction ofrotation of the rotor I5. Fluid is admitted to the spaces between theouter ends of the vanes as they move through whichever of the areas 29or 30 is at the time the inlet area as the vanes approach the workingspace 3|.l Each working space is located at the region of the greatestdiameter of the vane track 26 and extends circumferentially between theends of the ports or slots 36 and 31, and preferably for an arcuatedistance equal to or slightly greater than the distance between twoadjacent vanes I9. Each uid inlet area is thus at all times radiallyseparated from the uid outlet area ot the same fluid section by at leastone of the vanes I9 in cooperation with the vanevtrack 23 and thedifference in uid pressures on the opposite side faces of such'vanescauses the rotation of the rotor. rluid is discharged into whichever of,the areas is at the time the outlet area as the vanes recede from theworking spaces 3|. The

'surface of the vane track 26 within the working spaces 3| is preferablyconcentric with the rotor l5 and that intermediate the sealing arcs 21and the working spaces is given any suitable curvature producingsatisfactory rates of inward and outward movement of the vanes I9 as therotor revolves. y The sides or axial ends of the working spaces. thefluid areas 29 and the fluid areas 36 are deiined by a pair of matingdisc-shaped members |34 and |35 (Fig. 2), for convenience termed "endplates, which are provided with holes at their centers through whichpass the hubs I6 of the rotor |52 The outer surfaces'of the end plates|34 and |35 t snugly against the adjacent wall surfaces of the casing I0and cover II respectively and form substantially fiuidtight fits withthe several ports and passages to be presently described. The inner oropposing faces of the end plates |34 and |35 form uidtight ts with thesides of the vane track ring 25 by which they are axially positionedwith respect to the rotor I5 in such manner that the rotor is permittedto turn freely while itssides and the sides of the vanes I9 formsubstantially fluidtight running ts with the adjacent faces of the endplates |34 and |35. The end plate I 34 will hereinafter be termed thecasing end plate and similarly the end plate |35 will be termed thecover end plate.

Each of the end plates |34 and |35 is formed with two pairs of arcuateslots 36 and 31 respectively as shown in Figs. 3 to 5. Either pair ofthese ports may be the inlet ports and the other pair will then be theoutlet ports depending upon the direction of iiow of uid in the circuit;that is to say, the pair of ports 36 .will be the inlet ports and thepair of ports 31 will be the outlet ports when the conduit 42 isconnected with the supply pipe 38 and working pressure fluid flowstherethrough to the motor whereas the pair of ports 31 will be the inletports and the pair of ports 36 will be the outlet ports when therotatable body 9| of the reversing valve 90 is rotated to connect theconduit 43 with the supply pipe 38.- The ow of iiuid to and from theouter ends of the vanes I9 takes place only through the ports 36 and 31lof the casing end plate |34. The ports 36 and 31 of the cover end plate|35 function principally as balance ports to contain fluid under thesame pressure as that in the corresponding ports of the casing end plate|34 in order to produce hydraulic balance .of the rotating parts asalready stated.

The portion of the uid circuit for conveying uid to and from the outerends of the vanes I9 also includes a pair of channels 40 and 4|respectively (Figs. 2 and 5) which are formed in the casing I0 and whichare approriately connected end plate |34. With the arrangementhereinbefore described, operating pressure fluid admitted to the conduit42 will pass into the ports 36 of the casing end plate |34 and the fluidareas 29 connected with said ports 36 which will then be the inlet areasas above explained. Operating pressure fluid acting onthe adjacent facesof the vanes I1 that are then in contact with the portion of the vanetrack within the working spaces 3| will cause rotation of the rotor I5and shaft 22 in a clockwise direction as viewed in Fig. 3. The fluidareas 30 connected with the ports 31 of the casing end plate |34 willthen be the outlet or discharge areas and the fluid discharged by theouter ends of the vanes will pass out through the ports 31 of said endplate |34, into the channel 4I and out through the conduit 43. Similarlyoperating pressure fluid admitted to the conduit 43 will pass to theports 31 of the casing cheek plate |34 causing rotation of the rotor I5and shaft 22 in a counter clockwise direction as viewed in Fig. 3, andfluid exhausted by the outer ends of the vanes I9 will pass out throughthe ports 36 of the casing end plate |34 into the channel 40 and finallyout through the conduit 42.

With the parts in the position shown in Fig. 3, working or operatingpressure fluid entering the fluid areas 29 will act against the adjacentfaces of the vanes I9 which at the instant are in contact with the arcs3| of the vane track 26 and the force thus exerted will produceclockwise rotation of the rotary assembly and the driven shaft 22 asviewed in Fig. 3. In order for this operation to take place, however, itis necessary that the vanes I9 which separate the areas 29 from thefluid areas 3|! at the arcs 3| be firmly in contact with the vane trackand that there be similar contact between the ends of the vanes I9 andthe vane track at the sealing arcs 21. It is also important andpractically essential for quiet operation that contact between the vanesI9 and` the vane track be maintained throughout the movement of thevanes I9 through the fluid inlet areas, as sudden and abrupt outwardmovement of the vanes ywould otherwise result and would produce noise,wear and unsatisfactory operation. This contact of the vanes I9 at thearcs A21 and 3| and the track-following action of the vanes I9 as theypass through the fluid inlet areas will not dependably result howeverunless the vanes I9 are acted upon by an adequate radially-outwardforce.

In the motor herein shown this force is produced and brought to bear onthe inner ends of the vanes by improved means for continuously supplyingto the inner ends of all the vanes fluid having a controlled pressurehigher than that of the fluid in the inlet areas. The means employed 'Jrthis purpose will now be described.

As shown in Figs. 3 to 5, the end plates |34 and |35 are each formedwith an annular vane slot port |48 which continuously connects with theinner ends of all the vane slots I8. In order that these vane slot ports|48 may receive a supply of fluid, the vane slot port |48 in the" coverend plate |35 is connected with the branched ends of a pipe 52 as shownin Figs. 1 and 2. The fluid connections between the vane slot port |48and the cover end plate |35 and the branched ends of the pipe 52 includea hole drilled through the cover end plate |35 (Figs. 2 and 4) whichconnects said Vane slot port |48 with a groove 50 recessed in the outerface of the cover end plate |35, that is, the face adjacent the wallsurface of the cover II. Each groove 50 registers with an axial passage5| extending through'the cover II to which its end of the branch pipe.52 is suitably connected as shown in Fig. 2. The vane slot port |48 inthe casing end plate |34 is not directly connected with the fluidsupply, but receives its supply of fluid through the inner ends of thevane slots I6 and thus acts in part as a balance port to balance thehydraulic force acting on the sides or axial ends of the vanes I9 andthe rotor I5.

The present invention also includes improved means whereby the pressureof the fluid supplied to the vane slot ports |48 is at all timescorrelated with and exceeds by a substantially constant amount thepressure of the fluid actually existing in whichever of the fluid areasare at the time the inlet areas. This difference in pressure ismaintained irrespective of the amount of pressure in the. fluid inletareas or frequency of change thereof, and the means by which this isaccomplished will now be described.

Referring to Fig. 1, the inlet pipe 38 is provided Awith a valve 66which includes a Valve body 6I slidably mounted in the valve boretherein and which is urged Iinward toward its fully closed position by aspring 62. The inner end of the valve body 6I is adapted to be actedupon at all times by the pressure of the fluid in the valves fluidreceiving port 63 and is accordingly provided with a small stop 65 toprevent its inner end surface from contacting the closed end of thevalve bore when said valve body 6I is in its fully closed position asshown in Fig. 1. The outer end of the valve body 6|, which has the samearea as the inner end thereof, is similarly adapted to be acted upon byfluid having the same pressure as that in the valves fluid dischargingport 64 and the outer end of the valve bore is accordingly connectedwith said discharging port 64 as by a passage 66 which enters the valvebore at a point which will not be covered when the valve body 6| is inits fully open position.

When operating pressure fluid is admitted to the inlet pipe 38 it passesfirst to the valves receiving port 63 where it acts upon the inner endof the valve body 6| andy raises said valve bo'dy 6I against the spring62. This movement of the valve body 6| opens the valve 60 and permitspressure fluid to pass into the valves discharging port 64 whence itimmediately passes into the outer end of 'the valve bore and acts uponthe outer end of the valve body 6|. Two oppositely acting forces arethus brought to bear upon the Valve body 6|, the force tending to moveit outward comprising the action of the pressure fluid against its innerend and the opposing force tending to move the valve body 6| inwardcomprising the force exerted by the pressure fluid acting upon its outerend in combination with the force exerted by the spring 62. The Valvebody 6I is accordingly moved until the opposing forces balance, in whichposition it provides an orifice through the bore of the valve 60 of theproper size to create the necessary difference of pressures of the fluidin the receiving port 63 and discharging port 64 respectively, due tothe resistance of iiow through said orifice, as determined by the spring62.

As the areas of the inner and outer ends of the valve body 6I are equal,this balancing of forces acting on the valve body 6I is determinedentirely by relative pressures existing in the receiving port 63 anddischarging port 64 respectively and is independent of absolutepressures; that is to say, substantially the same difference existsin-these pressures regardless of the actual amount of pressure in eitherof said ports. This difference is therefore maintained substantiallyconstant throughout the entire range of operating pressures. The valvebody 6| will also move immediately to compensate for any change inoperating conditions, such as variation `in the amount of fluid passinginto the inlet pipe 38, change in viscosityof the operating fluid,etc.The pressure of the fluid in the valves discharging port 64 issubstantially the same as the pressure in whichever u1 the areas 29 or30 are at the time the inletl areas of the motor and is determined bythe motors load. The valvef60 therefore operates to maintain the iluidin its receiving port 63 at a pressure higher by a substantiallyconstant amount than the pressure of the fluid in whichever areas of themotor are its inlet areas. This difference in pressures is maintainedunder all operating conditions. The higher pressure in'the valvesreceiving port 63, and consequently in its connected portion of the pipe38, is accordingly termed the differential high pressure. i

i The pipe 52 is connected with the fluid inlet pipe 38 at a point whereit will always receive the differential high pressure fluid. As shown inFig. 1, this connection isv made with the iluid inlet pipe 38 at a pointin advance of the valve 60, i. e. with the portion of the fluid inletpipe 38 which leads to the valves receiving port 63. The pipe 52 andhence also the vane slot ports |48 thus always receive a supply of thedifferential high pressure fluid, the pressure differential of which ismade sufficient to force outward and to maintain proper contact betweenthe ends of the vanes I9 and the vane track 26. The innerv ends of all/the vanes I9 are thus continuously supplied with iluid having suflicientpressure to keep them in proper operating position regardless of thedirection in which the motor is being operated, and the pressure of thisfluid is always definitely related by a relatively constant differenceto the pressure of the working pressure fluidgreat, may be varied asconditions require but is preferably kept at the minimum.

Another feature of the arrangement shownin Fig. 1 is that it assuresproper contact between the ends of 'the vanes I9 and the vane track 26before any pressure iluid is admitted to the fluid inlet areas where itcan act upon the exposed ends of said vanes. This is due to the factthat the valve body 6I completely cuts oi communication between theportions of the pipe 38 which are connected with the receiving port 63and discharging port 64 Whenever the difference in pressures is lessthan the amount determined by the spring 62, as would be true when themotor is not in operation. Thus no fluid can pass through the valveuntil thevpressure in its receiving port 63 (and hence in the vane slotports |48) rises sufficiently to lift the valve body 6| against thespring 62; that is to say, until the differential high pressure has beenestablished. 'Ihe vanes I9 will therefore be forced into their properoperating positions a slight time before the operating pressure fluidstrikes their outer ends. This is important at starting and assures that2,255,786 l 4 the motor will begin to operate promptly, smoothoutward totheir operating positions and thatl immediately thereafter operatingpressure fluid will act against the exposed ends of the vanes I9 at thearcs 3|, as already explained, to produce rotation of the rotor I5 anddriven shaft 22. It will valso be seen thatV the differential highpressure acts to maintain proper operating position ofthe vanes I9 aslong as any fluid passes through the valve 60, that is to say, wheneverthe motor is in operation. The direction of rotation of the rotor I5 andshaft 22 are determined by the position of the rotatable body 9| of thereversingrvalve 90. With the rotatable body 9| in the position shown inFig. 1, working pressure fluid from the pipe 38 will pass into theconduit 42 and as already explained will pass to the ports 36 and fluidareas 29 to cause clockwise rotation of said rotor and shaft. Therotation of the rotatable body 9| through 96 in a clockwise directionwill connect the fluid supply pipe 38 with the conduit 43 so thatworking pressure `fluid will pass through the ports 3l and fluid areas30 and will cause rotation of the rotor I5 and shaft 22 ln a.counter-clockwise direction as viewed in Fig. 3. Differential highpressure fluid is continuously supplied to the inner ends of al1 thevanes (i. e. in both directions of rotation of the rotor I5 and alsoduring the entire time that reversal of its direction of rotation isbeing effected) so that the motor will start smoothly and operatesatisfactorily in either direction of rotation. The operation of themotor and speed of rotation of the rotor I5 and shaft 22 are regulatedand controlled by the amount of working pressure fluid admitted to thesupply pipe 38, which may be controlled by any suitable means, notshown.

This arrangement has many advantages. For example, the structure isextremely simple and inexpensive. .A rotary vane type fluid motorconstructed according to the present invention 'will start smoothly andpromptly in either direction of rotation and will also operate `smoothlyand satisfactorily at all speeds'from very low speeds vup to speeds thatare relatively high .-n

both directions of rotation. Such a motor has distinctive properties ofacceleration and deceleration because its rotating masses are small andthe working parts are substantially balanced 'With respect to hydraulicforces imposed thereon. For this reason the motormay be reversed veryrapidly and in practice such reversal under inertia load has beeneffected at rates up to and including approximately 60 reversals perminute with the rotor attaining an approximate speed of 1100 R. P. M.

The arrangement shown in Fig. 6 differs from that of Fig. 1 only in themeans by which the differential high pressure fluid is obtained. Thebranched pipe 52 is in this instance connected with the discharge portof a small auxiliary vexcess iluid not needed by the vane slot ports |48exhausts through the valve 60 into the pipe 38 and the valve 60 acts tomaintain a differential in the pressures of the fluid in the pipes 38and |52 respectively in a manner similar to that valready explained. Thepressure of the uid in the pipe 52 and hence in the vane slot portsconnected therewith is thus definitely related to the pressure of thefluid in the pipe 38fwhich is substantially the same as the pressure in`whichever of the areas are at the time the fluid inlet areas, and thedifferential in pressures is continuously maintained.

The inlet port of the pump is preferably connected as by a pipe with thefluid inlet pipe 38, so that its supply of fluid has the same pressureas that of the fluid in said pipe 38. This has the advantage of reducingthe work of the pump |10, as it is then necessary for said pump |10 toincrease the pressure of the iiuid only by the amount of the pressuredifferential, which is a relatively smallv amount. This makes itpossible to use a less expensive pump lthan would otherwise be requiredfor this purpose. The arrangement of Fig. 6 also has the advantage ofreducing the volume of ui'd raised to the differential highA pressurelevel to only a little more than must be supplied to the vane slot portsin order to obtain proper vane action.

The embodiment of Fig. 6 operates as a reversible vane type i'luidmotorin the same manner as already explained in connection with theembodiment illustrated in Figs. 1 to 5 and pro-- vides equallysatisfactory operation in both directions of rotation.

It will` be understood that the several embodiments of my invention havebeen' described for the purpose of illustrating the operation andconstruction of the apparatus of my present invention and that changesmay be made without departing from the spirit of theinvention.

I claim:

1. In a reversible rotary vane type fluid motor having a rotor providedWith a plurality of vanes movable inwardly and outwardly thereof, acasing therefor including a vane track for guiding the vanes in their inand out movement, a chamber adjacent the rotor having on thecircumferential sides thereof two fiuid areas eithr of which may be theinlet area and the other of which will then be the outlet area, saidchamber functioning as a Working chamber for whichever of said areas isat the time the inlet area and extending in a circumferential directiona distance substantially equal to the distance between the outer ends ofa pair of adjacent vanes when in contact with the portion of the vanetrack in said chamber, means for connecting either of said areas withworking pressure fluid to thereby make it the inlet area and means foruninterruptedly supplying to the inner ends of the vanes through atleast a portion of their rotary travel fluid under pressure higher thanthe greatest pressure then existing in either of .said areas,irrespective of which area is at the time the inlet area and during theperiod of reversal of the direction of rotation of the rotor.

2. In a reversible krotary vane type uid motor, having a rotor providedwith a plurality of vanes movable inwardly and outwardly thereof in asubstantially radial direction, a casing therefor including a track forguiding the vanes.

5 each Working chamber having on opposite circumferential sides thereoftwo iiuid areas either of which may be the inlet area and the other ofwhich will then be the outlet area, said cham-'- bers and areas beingpositioned adjacent the rotor whereby the radially outer ends of saidvanes are subjected to the respective pressures of the fluid therein asthey pass therethrough, means for connecting either of the two fluidareas adjacent one of said working chambers and the diametricallyopposed fluid area adjacent the other of said working chamberswithWorking pressure fluid to thereby make them the inlet areas and meansfor continuously supplying to theinner ends of the vanes, throughout atleast the portion of their rotary movement in which the outer ends arepassing intermediate the areas which at the time are the outlet areas,fluid having a pressure greater than but related to the pressure of saidworking pressure fluid, irrespective of which of said areas are theinlet areas and during the period in which the Working pressure fluid isbeing disconnected from one pair of diametrically opposed areas andconnected with the other. I

3. In a reversible rotary vane type iiuid motor having a, rotor providedwith a plurality of vanes movable inwardly and outwardly thereof, acasing therefor including a vane track for guiding the vanes in their inand out movement, two fluid areas either of which may be the inlet areaand the other of which will then be the outlet area, means forconnecting at will either of said areas with working pressure fluid tothereby make it the inlet area, a port connected with the inner ends ofsaid vanes during at least a portion of their rotary movement, and meansfor maintaining in said port a iiuid pressure correlated with thepressure of the working pressure uid and sufticient in amount to produceon the inner end of each vane in communication with said port an outwardforce exceeding the opposing inward force simultaneously exerted on saidvane by action of pressure fluid on the outer end thereof, whereby saidvane is kept in contact with said track throughout the time that itsinner end is connected with said port irrespective of which of saidareas is connected with the working pressure uid.

4. In a reversible rotary vane type fluid motor having a rotor providedwith a plurality of vanes movable inwardly and outwardly thereof, acasing therefor including a vane track for guiding the vanes in their inand out movement, a working chamberadjacent the rotor having on oppositecircumferential sides thereof two iluid areas either of which may be theinlet area and the other of which will then be the outlet area, meansfor connecting either of said areas with working pressure iiuid to makeit the inlet area and means continuously supplying to the inner ends ofall of said vanes uid under pressure greater than but related to thepressure of said working pressure fluid irrespective of changes inpressure in said working pressure fluid and irrespective of which ofsaid areas is at the time the inlet area and during the period in whichthe working pressure fluid is being disconnected from one of said areasand connected with the other.

5. In a. reversible rotary vane type fluid motor having a rotor providedwith a plurality of vanes movable inwardly and outwardly thereof, acas-` ing therefor including a vane track for guiding 'vanes in their inand 'out movement and provided adjacent the rotor with a working chamberhaving onl opposite circumferential sides thereof two fluid areas eithero f whichmay be the'inlet area and the other of which will then be theoutlet area, a supply line for the workating and to establish suchcommunication only after'a predetermined diilerence in pressures existson the inlet and outlet sides of said differential pressure valve, asupply port adapted to continuously connect with the inner ends of allof said vanes, and a fluid connection leading to said supply port from apoint in said supply line in advance of said dierential pressure valve.

16. In a reversible rotary vane type fluid motor having a rotor providedwith a plurality of vanes movable inwardly and outwardly thereof, acasing therefor includingv a vane track for guiding the vanes in theirin and out movement and provided adjacent the rotor with a workingvchamber having on opposite circumferential sides thereof two fluidareas either of which may be the inlet area and the other of which willthen be the outlet area, a supply port adapted to continuously connectwith the inner ends of al1 of said vanes, a pump having a dischargeconduit and adapted to deliver into said discharge conduit a volume ofiluid in excess of the volume required by the inner ends of said vanes,ailuid connection between said discharge conduit and said supply port, asecond fluid connection berelated to and greater than the pressure ofsaid working pressure uid.

8.y In a reversible rotary vane type fluid motor having a rotor providedwith a plurality of vanes movable inwardly and outwardly thereof, acasing therefor including a vane track for guiding the vanes in their inand out movement, two fluid areas either of which may be the inlet areaand the other of which will then be the outlet area, separateunrestricted fluid supply connections leading to said areas, a reversingvalve 'for supplying fluid pressure to either of said connections atwill, said motor casing having a port for supplying fluid pressure tothe inner ends of said vanes during at least a part of their rotarymovement andl means for maintaining in said port fluid pressure greaterthan the pressure in the inlet area irrespective of which of said fluidareas the inlet area.

9. The combination of a reversible rotary vane type fluid pressuredevice having a rotor including a plurality of vanes movable inwardlyand outwardly thereof, a, casing therefor including a track for guidingthe vanes in their in and out movement and provided with a workingcham-4 ber having interchangeable high and low pressure areas onopposite circumferential sides thereof adjacent the rotor, the outerends of tween said discharge conduit and the supply of working pressurefluid and valve means in said last named fluid connection active toregulate theilow therethrough of excess fluid delivered by said pump tomaintain the fluid in said discharge conduit under pressure related toand greater than the pressure of said working pressure fluid.

`'1. In a reversible rotary vane type fluid motor having a rotorprovided with a plurality of vanes movable inwardly and outwardlythereof, a casing therefor including a vane track for guiding the vanesin their in and out movement and provided adjacent the rotor with aworking chamber having on opposite circumferential sides thereof twoiluid areas either of which may be the inlet area and the other of whichwill then be the outlet area, a supply line for said working pressurefluid, a booster pump having its inlet port connected with and receivingits supply of iluid from said supply line, said booster pump also havinga discharge conduit and delivering into said discharge conduit fluid inexcess of the volume required by the inner ends ofz said vanes, a vaneslot port adapted to conthe ow therethrough of the excess fluiddelivered by said booster pump to maintain the fluid in said' dischargeconduit under pressure said vanes being subject to the respectivepressures in said chamber and said areas while passing therethrough, asource of pressure fluid continuously connected with the inner ends ofsaid vanes during atleast a portion of each rotation of the rotor andmeans for maintaining the pressure of the fluid connected to the innerends of said vanes at a pressure greater than but correlated to -thegreatest pressure existing at the time in either of said areas,irrespective of which of said areas is `the high pressure area andduring the interval of interchange of high pressure from one area toanother.

' 10. The combination of a reversible rotary vane type fluid motorhaving a rotor including a plurality of vanes movable inwardly andoutwardly thereof, a casing therefor including a track for guiding thevanes in their in and out movement and provided with a working chamberhaving interchangeable high and low pressure areas on oppositecircumferential sides thereof adjacent the rotor, the outer ends of saidvanes being subject to the respective pressures in said chamber and saidareas while passing therethrough, a pressure fluid line, uid flowcontrol means connected with said line and with the exhaust and havingtwo connections with said motor one witheach of said areas. said fluidflow control means having an element movable to connect said line witheither of saidareas or with the exhaust, a source of pressure fluidcontinuously connected with the inner ends of said vanes during at leasta portion of each rotation of the rotor and means for maintaining thepressure of said fluid connected to the inner ends of said vanes at apressure greater than but correlated to Ithe greatest pressure existingin either of said areas, irrespective of whether said supply line isconnected with one of said areas or with the exhaust.

ll. In a 'reversible vane type rotary uid motor, a rotorhaving aplurality of vanes movable inwardly and outwardly thereof, a vane trackfor guiding said vanes in their in and out movement, interchangeableinlet and outlet ports for the outer ends of said vanes, an inlet portfor the inner ends of said vanes, a reversing valve having unimpededfluid connections with the inlet and outlet ports for the outer ends ofsaid vanes, a supply pipe leading to said reversing valve, a supply pipeleadingfto the inlet port forl the inner ends of said vanes and meansfor main- 5 taining a differential pressure relationship between thefluids in said supply pipes.

12. The combination of a reversible rotary vane type fluid pressuredevice having a rotor including a plurality of vanes movable inwardlyand outwardly thereof, a vcasing therefor including a track for guidingthe vanes in their in and out movement and provided with a Workingchamber having interchangeable high and low pressure areas on oppositecircumferential sides thereof adjacent the rotor, the outer ends of saidvanes being subject to the respective pressures in said chamber and saidareas while passing therethrough, a port arranged to connect with theinner ends of said vanes during at least a portion of each rotation ofthe rotor, a pump 20 having a discharge conduit connected with said portandl means for maintaining the pressure of the fluid supplied by saidpump to said port at a pressure correlated with the pressure of thefiuid in whichever of the areas is the high pres-V sure area andsufcient in amount to produce on the inner ends of the vanes aradially-outward force exceeding the 'greatest radially-inward forcesimultaneously exerted on saidvanes by action of pressure fluid on theouter ends thereof, irrespective of which of said areas is at the timethe high pressure area and during the interval of interchange of high.pressure from one are to another. l

13. In a reversible rotary vane type fluid mo- 3 tor having a. rotorprovided with a plurality of vanes movable inwardly and outwardlythereof in a substantially radial direction in slots formed therein, acasing therefor including a track for guiding the vanes in their in andout movement, two fluid areas either `of which may be the inlet area andthe other of which will then be the outlet area, means for connectingat; will either of said areas with working pressure fluid to make it theinlet area, a pair of substantially co-extensive mating ports disposedon axially opposite sides of the rotor and arranged -to connect with theinner ends of the vanes during at least a portion of their rotarymovement, said ports being positioned.axial1y opposite onel anothei`whereby the force exerted in an axial direction on said rotor and vanesby pressurefiuid in one of said ports is opposed and substantiallybalanced by the force exerted on said rotor and vanes by pressure fluidin the other of said ports, and means for maintaining in said portsiluid pressure correlated with the pressure of the working pressurefluid and sufficient in amount to` produce on the inner end of each vanein communication therewith an outward force exceeding the opposinginward force simultaneously exerted on said vane by action of pressurefluid on the outer end thereof, whereby said vane is kept in contactwith said track throughout the time that its inner end is connected withsaid ports irrespective of which of said areas is connected with theworking pressure fluid, said last named means comprising a supply ofsaid fluid l of correlated pressure ,and means directly connecting saidsupply with only one of said ports, with the other port of said matingpair connected with said supply solely through said first named port andthe inner ends o1' said slots.

CHARLES KENDRICK.

